List of top Electronics and Communication Engineering Questions on Signals and Systems

The convolution of two DT sequence is,
\( x(n) = \{1 \uparrow, 2, 0, 1\} \)
\( h(n) = \{2, 2, 3\} \)

Consider a causal LTI system with frequency response \( H(j\omega) = \frac{1{j\omega + 3} \). This system produces the output to an input \( x(t) \) as \( y(t) = e^{-3t}u(t) - e^{-4t}u(t) \). The input \( x(t) \) is

A system is described by the differential equation \( \frac{d^2y(t){dt^2} + 6\frac{dy(t)}{dt} + 5y(t) = x(t) \). Impulse response of the system is

Find the convolution sum of sequences \(x_1[n] = \{1, 2, 3\}\) and \(x_2[n] = \{2, 1, 4\}\).

Which of the following systems is memoryless?

Find the ROC of \(x(t) = e^{-2t u(t) + e^{-3t} u(t)\).

For a WSS random process, the autocorrelation $R_x(\tau)$ as $\tau \rightarrow \infty$ approaches:

The total average power of a signal equals:

In a causal and stable LTI system, the impulse response $h(t)$ must satisfy which condition ?

Signal distortionless transmission through an LTI system requires:

The random process \(X(t)=A\cos(\omega_0 t+\theta)\) is wide-sense stationary, where \(A\) and \(\omega_0\) are constants and \(\theta\) is a uniformly distributed random variable on the interval \((0,2\pi)\). Then the mean value is

Determine the z-transform corresponding to the given pole-zero plot.

A linear time-invariant system is characterized by \[ H(z)=\frac{3-4z^{-1}} {1-3.5z^{-1}+1.5z^{-2}}. \] Which of the following is not correct?

If all the frequency components of the input signal undergo the same time delay, then the value of the group delay of the system is

The Fourier Transform of the sampled signal is given by

Determine the conditions on the sampling interval \(T\) such that \[ x(t)=\frac{\cos(2\pi t)\sin(\pi t)}{\pi t} + \frac{2\sin(6\pi t)\sin(2\pi t)}{\pi t} \] is uniquely represented by the discrete-time sequence \(x[n]=x(nT)\).

\(N\)-point DFT using FFT algorithms (radix-2) requires the following complex multiplications

A relaxed linear time-invariant system with impulse response \[ h(n)=a^n u(n), \qquad |a|<1 \] when the input is a unit step sequence, \[ x(n)=u(n), \] then the output \(y(\infty)\) of the system is

Determine the z-transform of the signal \[ x(n)=a^n(\sin\omega_0 n)u(n) \]

A square-law system is/has

If the input is \[ x[n]=-u[n]+2u[n-3]-u[n-6] \] and impulse response is \[ h[n]=u[n+1]-u[n-10] \] of an LTI system, then the output \(y[n]\) in the interval \(5\le n\le9\) is

Overlap in the shifted replicas of the original spectrum after sampling is termed

The impulse response of an RL circuit is a

Consider the statements given below: A. Discrete-time LTI system with impulse response $h[n] = \left(\frac{1}{2}\right)^n u[n-1]$ is causal B. Response $(-2)^n u[n]$ may or may not be stable C. Response $(-2)^n u[n]$ is unstable D. Response $(-2)^n u[-n-1]$ is unstable